<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>7. 实参的数量形参的数量</title>
</head>
<body>
<script>
    function foo(a, b, c, d) {
        //arguments.length是实参的数量
        console.log(arguments.length)
        //函数的长度是形参的数量
        console.log(foo.length)
    }

    foo(1, 2, 3, 4)
    foo(1)
    foo()

</script>
</body>
</html>